Articulating mechanism with flex-hinged links

ABSTRACT

A surgical tool comprises a pair of opposing jaws moveable relative to each other between a closed position and first and second open positions. The opposing jaws remain substantially parallel to one another when moving between the closed position and the first open position and remain non-parallel to one another when moving between the first open position and the second open position.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.10/948,911, filed on Sep. 24, 2004, issued as U.S. Pat. No. 7,678,117 onMar. 16, 2010, which claims benefit of U.S. Provisional Application No.60/577,757, filed Jun. 7, 2004. The contents of which are herebyincorporated by reference into the present disclosure.

BACKGROUND OF THE INVENTION

This invention relates to articulating mechanisms and applicationsthereof, including the remote steering, guidance and/or manipulation ofinstruments and tools.

The ability to easily remotely steer, guide and/or manipulateinstruments and tools is of interest in a wide variety of industries andapplications, in particular where it is desired to navigate aninstrument or tool into a workspace that is not easy to manuallynavigate by hand or that might otherwise present a risk or danger. Thesecan include situations where the targeted site for the application of atool or instrument is difficult to access, e.g. certain surgicalprocedures, or the manufacture or repair of machinery, or evencommercial and household uses, where manual access to a targeted site isrestricted or otherwise. Other situations can include e.g industrialapplications where the work environment is dangerous to the user, forexample, workspaces exposed to dangerous chemicals. Still othersituations can include e.g. law enforcement or military applicationswhere the user may be at risk, such as deployment of a tool orinstrument into a dangerous or hostile location.

Using surgical procedures as an illustrative example, procedures such asendoscopy and laparoscopy typically employ instruments that are steeredwithin or towards a target organ or tissue from a position outside thebody. Examples of endoscopic procedures include sigmoidoscopy,colonoscopy, esophagogastroduodenoscopy, and bronchoscopy.Traditionally, the insertion tube of an endoscope is advanced by pushingit forward, and retracted by pulling it back. The tip of the tube may bedirected by twisting and general up/down and left/right movements.Oftentimes, this limited range of motion makes it difficult to negotiateacute angles (e.g., in the rectosigmoid colon), creating patientdiscomfort and increasing the risk of trauma to surrounding tissues.Laparoscopy involves the placement of trocar ports according toanatomical landmarks. The number of ports usually varies with theintended procedure and number of instruments required to obtainsatisfactory tissue mobilization and exposure of the operative field.Although there are many benefits of laparoscopic surgery, e.g., lesspostoperative pain, early mobilization, and decreased adhesionformation, it is often difficult to achieve optimal refraction of organsand maneuverability of conventional instruments through laparoscopicports. In some cases, these deficiencies may lead to increased operativetime or imprecise placement of components such as staples and sutures.Steerable catheters are also well known for both diagnostic andtherapeutic applications. Similar to endoscopes, such catheters includetips that can be directed in generally limited ranges of motion tonavigate a patient's vasculature.

There have been many attempts to design endoscopes and catheters withimproved steerability. For example, U.S. Pat. No. 3,557,780 to Sato;U.S. Pat. No. 5,271,381 to Ailinger et al.; U.S. Pat. No. 5,916,146 toAlotta et al.; and U.S. Pat. No. 6,270,453 to Sakai describe endoscopicinstruments with one or more flexible portions that may be bent byactuation of a single set of wires. The wires are actuated from theproximal end of the instrument by rotating pinions (Sato), manipulatingknobs (Ailinger et al.), a steerable arm (Alotta et al.), or by a pulleymechanism (Sato). U.S. Pat. No. 5,916,147 to Boury et al. discloses asteerable catheter having four wires that run within the catheter wall.Each wire terminates at a different part of the catheter. The proximalend of the wires extend loosely from the catheter so that the physicianmay pull them. The physician is able to shape and thereby steer thecatheter by selectively placing the wires under tension.

Although each of the devices described above are remotely steerable,their range of motion is generally limited. The steering mechanisms mayalso be laborious to use, such as in the catheter of Boury et al. whereeach wire must be separately pulled to shape the catheter. Further, inthe case of e.g. endoscopes and steerable catheters that use knob andpulley mechanisms, it requires a significant amount of training tobecome proficient in maneuvering the device through a patient's anatomy.

Consequently, a device with enhanced remote maneuverability tocontrollably navigate complex geometries may allow more efficient andprecise advancement and deployment of instruments and tools. It wouldalso be advantageous for such a device to provide a more intuitive andfacile user interface to achieve such enhanced maneuverability. Such adevice would have widespread application in guiding, steering and/ormanipulating instruments and tools across numerous industries. Such adevice would also of itself have entertainment, recreation andeducational value.

BRIEF SUMMARY OF THE INVENTION

The present invention provides articulating mechanisms and componentsthereof useful for a variety of purposes including but not limited tothe remote manipulation of instruments and tools. Such instruments andtools can include surgical or diagnostic instruments or tools, includingbut not limited to endoscopes, light sources, catheters, Doppler flowmeters, microphones, probes, retractors, dissectors, staplers, clamps,graspers, scissors or cutters, ablation or cauterizing elements, and thelike. Other instruments or tools in nonsurgical applications include butare not limited to graspers, drivers, power tools, welders, magnets,optical lenses and viewers, light sources, electrical tools,audio/visual tools, lasers, monitors, and the like. Depending on theapplication, it is contemplated that the articulating mechanisms andcomponents of the present invention can be readily scaled to accommodatethe incorporation of or adaptation to numerous instruments and tools.The articulating mechanism may be used to steer these instruments ortools to a desired target site, and can further be employed to actuateor facilitate actuation of such instruments and tools.

In one variation of the invention, an articulating mechanism is providedthat includes multiple pairs of flexible segments, with each flexiblesegment of each pair being maintained in a spaced apart relationshiprelative to the other flexible segment of the pair. The flexiblesegments comprise a unit of at least one link and at least one flexiblehinge, with adjacent flexible segments in the mechanism joined byflexible hinges. The mechanism further includes at least one set ofcables connecting the flexible segments of at least one discrete pair toone another, such that movement of one flexible segment of the connectedpair causes corresponding relative movement of the other flexiblesegment of the pair. In further variations, additional cable sets areprovided that connect the flexible segments of additional discretepairs. The flexible segments can form proximal and distal ends of themechanism where movement of the proximal end of the articulatingmechanism results in corresponding relative movement of the distal end.For movement in two dimensions, the flexible hinges are aligned inparallel. For movement in three dimensions, at least one flexible hingeof the mechanism is oriented at an acute angle to at least one otherflexible hinge of the mechanism. For maximum range of motion in threedimensions, at least one flexible hinge is oriented orthogonal to atleast one other flexible hinge.

In another variation of the invention, flexible members for use inarticulating mechanisms are provided. The flexible members will includeone or more flexible segments joined together. The flexible members canbe formed with any number of flexible segments and can further beprovided with reciprocal means for axially connecting the memberstogether in lengthwise fashion. The flexible members can be used to forman articulating mechanism according to the present invention, oralternatively, can be incorporated into other mechanisms and devices. Inone variation, flexible member includes flexible hinges are oriented inparallel. In another variation, the flexible members include at leastone flexible hinge that is oriented at an acute angle to at least oneother flexible hinge. In a further variation, at least one flexiblehinge is oriented orthogonal to at least one other flexible hinge.

In further variations of the invention, flexible segments are providedthat can form or be incorporated into flexible members or articulatingmechanisms according to the invention. The flexible segments comprise aunit of at least one link and at least one flexible hinge. In certainvariations, these flexible segments are designed with flexible hingesthat bend or flex at particular predetermined positions, the locationsof which will have particular effects on cables running through thesegments. In particular, these predetermined positions will have animpact on the relative tautness of cables passing through the flexiblesegments. This impact, also referred to as cable pull bias, can benegative, neutral or positive. In one aspect, the predetermined flexposition provides for a negative cable pull bias where one or morecables passing through adjacent flexible segments will develop slackwhen the mechanism is bent or articulated. In another aspect, thepredetermined flex position provides a neutral cable pull bias, wherecable slack is reduced or eliminated when the mechanism is bent orarticulated. In yet another aspect, the predetermined flex positionprovides a positive cable pull bias where one or more cables associatedwith the flexible segment will have increased tension when the mechanismis bent or articulated. Each of these configurations may have advantagesdepending on the particular application at hand.

In further aspects of the invention, a tool or instrument may beattached to and extend from the distal end of the articulatingmechanisms, or the articulating mechanisms may be otherwise incorporatedinto such instruments or tools. In the case of surgical applications,examples of surgical or diagnostic tools include, but are not limitedto, endoscopes, light sources, catheters, Doppler flow meters,microphones, probes, retractors, dissectors, staplers, clamps, graspers,scissors or cutters, and ablation or cauterizing elements. For otherapplications, numerous tools or instruments are likewise contemplated,including without limitation, e.g., graspers, drivers, power tools,welders, magnets, optical lenses and viewers, electrical tools,audio/visual tools, lasers, light sources, monitors, and the like. Thetypes of tools or instruments, methods and locations of attachment, andapplications and uses include, but are not limited to, those describedin pending and commonly owned U.S. application Ser. Nos. 10/444,769 and10/928,479, incorporated herein by reference in their entirety.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1D show perspective views of an articulating mechanismaccording to one embodiment of the invention, with pairs of flexiblesegments connected by corresponding cable sets and having flexiblehinges oriented orthogonal to one another. FIG. 1A shows the mechanismin its natural, unactuated configuration. FIGS. 1B-I D show themechanism in different states of manipulation.

FIG. 2A is a perspective view of a flexible member according to anotherembodiment of the invention, with flexible segments having flexiblehinges oriented orthogonal to one another. FIG. 2B is a side view of theflexible segment of FIG. 2A. FIG. 2C is a cross-sectional view of theflexible segment as shown in FIG. 2B, taken along the plane designatedby line A-A.

FIGS. 3A and 313 are perspective and side views, respectively, of aflexible member according to yet another embodiment of the invention.FIG. 3C is a cross-sectional view of the flexible member of FIG. 3A,taken along the plane designated by line B-B.

FIGS. 4A and 4B are perspective and side views, respectively, of aflexible segment according to a further embodiment of the invention.FIG. 4C is a cross-sectional view of the flexible segment of FIG. 4A,taken along the plane designated by line C-C.

FIGS. 5A and 5B are perspective and side views, respectively, of aflexible segment according to yet another embodiment of the invention.FIG. 5C is a cross-sectional view of the flexible segment of FIG. 5A,taken along the plane designated by line D-D.

FIG. 6 is a side sectional view of an articulating mechanism accordingto another embodiment of the invention, showing a scaling of movementbetween the proximal and distal end.

FIG. 7 is a side sectional view of an articulating mechanism accordingto yet another embodiment of the invention, showing a different scalingof movement between the proximal and distal end.

FIG. 8A is a perspective view of a surgical instrument incorporating agrasping tool and an articulating mechanism according to an embodimentof the invention. FIG. 8B is an enlarged view of the distal end of theinstrument of FIG. 8A, showing the grasping tool in greater detail.

FIGS. 9A and 98 show end and cross-sectional views, respectively, of thegrasping tool depicted in FIG. 8B in the closed position, with thecross-sectional view of FIG. 9B taken along the plane designated by line9B-9B in FIG. 9A.

FIGS. 10A and 10B show end and cross-sectional views, respectively, ofthe grasping tool depicted in FIG. 8B in a first open position (with thejaws remaining parallel) with the cross-sectional view of FIG. 10B takenalong the plane designated by line 10B-10B in FIG. 9A.

FIGS. 11A and 11B show end and cross-sectional views, respectively, ofthe grasping tool depicted in FIG. 8B in a second open position (withthe jaws having moved to a non-parallel position) with thecross-sectional view of FIG. 10B taken along the plane designated byline 10B-10B in FIG. 9A.

FIG. 12 is a perspective view of a flexible segment of yet anotherembodiment of the invention. FIG. 13 is an exploded view of the flexiblesegment of FIG. 12, showing the inner core and outer cover that form theflexible segment of FIG. 12.

FIGS. 14A and 14B show side and cross-sectional views, respectively, ofa flexible segment according to further embodiment of the invention, ina straight, unbent configuration. The cross-sectional view of FIG. 14Bis taken along the line designated 14B-14B in FIG. 14A.

FIGS. 15A and 15B show side and cross-sectional views, respectively, ofthe flexible segment FIGS. 14A-14B, in a bent configuration. Thecross-sectional view of FIG. 15B is taken along the line designated15B-15B in FIG. 15A.

FIG. 16A is a perspective view of a catheter incorporating a anarticulating mechanism according to an embodiment of the invention. FIG.16B is an enlarged view of the distal end of the catheter of FIG. 16A.

DETAILED DESCRIPTION OF THE INVENTION

Articulating mechanisms according to the invention generally includemultiple pairs of flexible segments and at least one set of cablesconnecting at least one discrete pair of flexible segments. In certainembodiments, the articulating mechanisms can be formed of flexiblemembers that are made of flexible segments and that can have varyingnumbers of links. The term “link” as used herein refers to a discreteportion of the mechanism, flexible member, or flexible segment that iscapable of movement relative to another discrete portion of themechanism, flexible member or flexible segment. Links are typically, butneed not be, cylindrical. The links are generally aligned along thelongitudinal axis of the mechanism, flexible member or flexible segment.Adjacent links of the mechanism, flexible member or flexible segment arejoined by flexible hinges. Terminal links of the articulating mechanism,flexible member or flexible segment can also be secured to orincorporated into other aspects of the mechanism or tools attached tothe mechanism. The term “flexible hinge” refers to a discrete sectionthat extends from a link and is capable of flexure. Flexible hinges aretypically, but need not be, oriented perpendicular to the longitudinalaxis of the mechanism, flexible member or flexible segment. Links andflexible hinges are typically, but not necessarily, integrally formedtogether. A “flexible segment” usually includes one or more adjacentlinks connected by flexible hinges. A flexible segment capable ofmovement in two dimensions with a single degree of freedom can have asingle flexible hinge that connects two links. A flexible segmentcapable of movement in three dimensions with two degrees of freedom canhave two flexible hinges oriented at an acute angle to one anotherconnecting to three links. For a maximum three-dimensional range ofmotion, the angle will be orthogonal. Flexible segments can provide thecomponent pieces of a flexible member or of an articulating mechanism. A“flexible segment pair” refers to a flexible segment at one end of themechanism that corresponds to another flexible segment at the oppositeend of the mechanism. Articulating mechanisms according to the inventionwill include a plurality of flexible segments that are members ofdiscrete pairs. The flexible segments are generally arranged to form aproximal end and a distal end, with one flexible segment of each pairbeing situated at the proximal end, and the other flexible segment atthe distal end. In order to achieve the greatest freedom of motion inthree dimensions, at least one flexible hinge of the mechanism isoriented orthogonal to at least one other hinge of the mechanism.However, the invention also contemplates configurations where flexiblehinges are oriented parallel or are offset at any acute angle.

A cable set can connect the flexible segments of a discrete pair to oneanother so that movement of one flexible segment of a pair causes acorresponding movement of the other flexible segment of the pair. Asused herein, the term “active flexible segment” or “active flexiblesegment pair” refers to flexible segments that are directly connected toone another by a cable set. The term “spacer flexible segment” or“spacer flexible segment pair” refers to flexible segments that are notdirectly connected by a cable set. Spacer flexible segments cannevertheless be disposed between active flexible segments and providefor the passage of cable sets that connect active flexible segments. Theability to manipulate active flexible segment pairs allows for themechanism to readily form complex three-dimensional configurations andgeometries as is further detailed herein, With conventional articulatingdevices that rely on cable sets or wires that pass through otherwiseunconnected links, it is difficult to obtain such complex geometriesbecause such devices are typically designed such that the steeringcables or wires pass through each link and terminate at a distal-mostlink. Thus, all the segments bend together in a coordinated response tomovement of the wire or cable set, typically in a curved, or arcuatefashion.

In addition to the formation of complex configurations, the presentinvention also allows for increased rigidity of the mechanism byconstraining manipulated active flexible segments and allowing suchsegments to resist movement due to laterally applied forces. A givenflexible segment pair is considered fully constrained if uponmanipulating the segment pair to achieve the desired shape, and fixingone segment of the pair in that desired shape, the other segment of thepair can resist loads while maintaining its desired, unloaded shape. Aminimum of two cables are required to fully constrain a single degree offreedom flexible segment that has two links and one flexible hinge. Fora two degree of freedom flexible segment having three links and twoflexible hinges (oriented either at an acute angle or orthogonally toone another) a minimum of three cables are required to fully constrainthe segment. This is not always the case with conventional articulatingdevices. Spacer flexible segments will not be so constrained, and theinclusion of such unconstrained spacer flexible segments may beadvantageous in many situations where it is desirable to have portionsof the actuated mechanism be less rigid

The terms “instrument” and “tool” are herein used interchangeably andrefer to devices that are usually handled by a user to accomplish aspecific purpose. For purposes of illustration only, articulatingmechanisms of the invention will be described in the context of use forthe remote guidance, manipulation and/or actuation of surgical ordiagnostic tools and instruments in remote accessed regions of the body.As previously noted, other applications of the articulating mechanismbesides surgical or diagnostic applications are also contemplated andwill be apparent to one of skill in the art. Generally any suchapplication will include any situation where it is desirable to navigatean instrument or tool into a workspace that is not easy to manuallynavigate by hand or that might otherwise present a risk or danger. Theseinclude, without limitation, industrial uses, such as for the navigationof a tool, probe, sensor, etc. into a constricted space, or for precisemanipulation of a tool remotely, for example, for the assembly or repairof machinery. These can also include commercial and household situationswhere the targeted site for the application of a tool or instrument isdifficult to access. Other situations can include e.g. industrialapplications where the work environment is dangerous to the user, forexample, workspaces exposed to dangerous chemicals. Still othersituations can include e.g. law enforcement or military applicationswhere the user may be at risk, such as deployment of a tool orinstrument into a dangerous or hostile location. Yet other uses includeapplications where simply remote manipulation of complex geometries isdesirable. These include uses in recreation or entertainment, such astoys or games, e.g, for remote manipulations of puppets, dolls,figurines, and the like.

Turning to the embodiment shown in FIGS. 1A-1D, articulating mechanism100 includes a plurality of flexible segments that form a proximal end121 and a distal end 122. Flexible segments 111 and 112, 113 and 114,115 and 116, 117 and 118 and 119 and 120, respectively, are each membersof a discrete pair, with one flexible segment of a pair (111, 113, 115,117 or 119) at proximal end 121 with the other (112, 114, 116, 118 or120) at distal end 122. As depicted, flexible segment 111 at proximalend 121 is formed of links 101, 103 and 105 connected by flexible hinges107 and 109 oriented orthogonal to each other. Cable channels 123 arelocated and pass through the periphery of each link for acceptingpassage and connection of cable sets. The flexible segment also includescentral channel 124 running through the longitudinal axis of theflexible segment to accommodate additional cables, wires, fiberoptics orother like elements associated with a desired tool or instrument used inconjunction with the mechanism. Paired flexible segment 112 at distalend 122 similarly is formed of links 102, 104 and 106 connected byflexible binges 108 and 110 oriented orthogonal to one another andlikewise including similar cable channels and central channel. Theremaining flexible segments of both the proximal end (113, 115, 117 and119) and distal end (114, 116, 118 and 120) have the same configurationwith the last link of one segment also functioning as the first link ofthe next segment. And as shown, each flexible hinge is orientedorthogonal to adjacent hinges. As previously noted flexible segments ofsuch configuration move in two degrees of freedom and are moveable inthree dimensions. The proximal flexible segments (111, 113, 115 and 119)are connected to the distal flexible segments (112, 114, 116 and 120) bysets of cables 131, 133, 135 and 139, respectively. These flexiblesegment pairs are thus active flexible segments. Flexible segments 117and 118 are not directly connected by a cable set and thus function asspacer segments. The mechanism further includes spacer element 125disposed between the proximal end 121 and the distal end 122 to provideadditional separation between the proximal flexible segments and distalflexible segments. The spacer element is optional, and may be of anylength appropriate to the intended application. It is configured toaccommodate all the cables that connect the flexible segment pairs, aswell as additional cables, wires, fiberoptics or other like elementsassociated with a desired tool or instrument used in conjunction withthe mechanism.

Each active flexible segment at the proximal end of the articulatingmechanism is connected to its corresponding active flexible segment atthe distal end by two or more cables. Each cable set may be made up ofat least two cables. As noted, movement of one active flexible segmentpair is controlled by its corresponding cable set and is independent ofany other flexible segment pair. In certain variations, for example, acable set will include three cables spaced 120 degrees apart. By using aset of three cables to connect an active flexible segment having atleast one flexible hinge oriented orthogonal to at least one otherflexible hinge, each active flexible segment pair can be manipulated ormoved in three degrees of freedom, independently of any other activepairs. These three degrees of freedom include up/down motion, left/rightmotion, and rotational or “rolling” motion. By combining a plurality ofactive flexible segments, multiple degrees of freedom are achieved,allowing the articulating mechanism to be shaped into various complexconfigurations. For example, the variation shown in FIGS. 1A-1D has atotal of four active flexible segment pairs each independently connectedby sets of three cables each, for possible motion in twelve degrees offreedom. Such multiple degrees of freedom are not available in typicalconventional mechanisms where only a single set of cables is employed tomanipulate the mechanism links.

As noted the flexible segments also include a plurality of channels forpassage of the cables that connect active flexible segment pairs, asshown. Cables, wires, fiberoptics, flexible endoscopes and the like, mayalso be run through a central channel provided in the flexible segments,if desired. Channels can also be provided to allow for passage of fluiddelivery tubes. The flexible segments can further be designed withattachment channels that communicate with the flexible segment exteriorfor mounting other elements, e.g., energy sources (for ablation orcoagulation) or fiberoptics, or flexible endosocopes, at the distal endof the articulating mechanism, More than one flexible segment mayinclude an attachment channel so that the attachment channel may extendfrom the distal end to the proximal end of the mechanism.

Referring to FIG. 1A, cables fixed to a proximal active flexible segmenttravel through spacer 125 to connect with a corresponding distalflexible segment of the pair. As shown in FIGS. 1B-1C, movement ofactive proximal flexible segments results in inverted, reciprocalmovement of active distal flexible segments. In other variation, thecables can be twisted or rotated 180 degrees while running throughspacer element 125 so that the reciprocal movement at the distal end 122is mirrored. The articulating mechanisms of this invention may beconfigured to include cables twisted in any amount between 0 degrees to360 degrees to provide for 360 degree range of reciprocal motion.

Spacer flexible segments, i.e., flexible segments not connected bydiscrete sets of cables (e.g., 117 and 118 in FIGS. 1A-1D), may also beincluded in the articulating mechanisms. These flexible segments can beinserted between active flexible segments at either the proximal ordistal ends or both, and act as flexible segments that are notindependently actuatable, but that do allow for pass through of cablesets to neighboring active flexible segments. Spacer flexible segmentscan be desirable for providing additional length to the proximal and/ordistal end of the mechanism. In addition the inclusion of spacerflexible segments (or a greater relative number of spacer flexiblesegments) at one end of the mechanism, allows for the proportionalscaling of movement or motion of the corresponding other end. Forexample, the inclusion of spacer flexible segments (or a greaterrelative number of spacer flexible segments) at the proximal end wouldrequire a more exaggerated movement by the user at the proximal end toachieve the desired motion at the distal end. This could be advantageousin situations where fine, delicate controlled movements were desired,such as, for example, situations where there is a risk that a user maynot possess the necessary dexterity to perform the desired procedureabsent such proportional scaling of the distal end movement or motion.Alternatively, spacer flexible segments (or a greater relative number ofspacer flexible segments) could be provided on the distal end, in whichcase the degree of distal end movements would be proportionally greaterthan those of the proximal end, which may also be desirable forparticular applications. In addition to the above, proportional scalingof movement or motion can also be accomplished by increasing ordecreasing the cable channel pattern radius of the flexible segments,either active or spacer, at either the proximal or distal end, as willbe further detailed herein.

Complex movements, including up, down, right, left, oblique, androtational movements, may be accomplished due to the formation of pairsof active flexible segments connected by discrete cable sets, asdescribed above. For example, in the variation shown in FIG. 1B, themost distal active flexible segment 112 at the distal end may beactuated, while all other flexible segments remain stationary, byactuation of the most proximal flexible segment 111 at the proximal end.Proximal segment 111 can further be manipulated such that distal-mostflexible segment 112 sweeps a right circular cone about longitudinalaxis Z1 of the mechanism, the base diameter of which increases with suchfactors as increased length of the flexible hinge, enhanced cableflexibility, and addition of spacer flexible segments between flexiblesegment 112 and the next adjacent active flexible segment. As, if notmore, importantly, proximal segment 111 can be rotated or “rolled” aboutits axis, represented as Z3 in FIG. 1B, and the resultant torquetransmitted through the mechanism to distal segment 112, such thatsegment 112 rotates about its axis, represented as Z2 in FIG. 1B.

As shown in FIG. 1C, the most proximal active flexible segment at thedistal end, 120, is actuated while all other flexible segments remainstationary by actuating only the most distal active flexible segment atthe proximal end, flexible segment 119. By manipulating the proximal endin this configuration, the distal end can sweep a right circular conewith a larger base diameter than that discussed above with respect toFIG. 1B, due to the increased number of segments distal to the actuatedsegment. Again, the proximal end can be rotated or “rolled” about itsaxis and the resultant torque transmitted through the mechanism to thedistal end.

Although a number of segment movements are depicted in FIGS. 1B-1D,other complex, 3-dimensional movements incorporating up, down, right,left, oblique and rotational movements, may also be accomplished. Forexample, FIG. 1D shows the distal end 122 of articulating mechanism 100having multiple curvatures along its length, each oriented in directionsindependent of one another. As noted, articulating mechanism 100 of FIG.1A-1D has four active pairs of flexible segments, each of which isconnected by a cable set having three cables, providing for movement intwelve degrees of freedom, but other configurations of flexible segmentpairs and cable sets will readily achieve similar complex movements andgeometries. The ability of portions the mechanism to bend in differentdirections at the same time and create active complex configurations isprovided by the independent actuation of each active flexible segmentpair as controlled through its corresponding cable set.

Turning to FIGS. 2A-2C, flexible member 200 includes flexible segments216, 218 and 220 formed by a series of links 202, 204, 206, 208, 210,212 and 214 connected by flexible hinges 231, 232, 233, 234, 235 and236, respectively. The flexible member terminates at either end at links202 and 214. Terminal link 202 includes cylindrical recess 223 andhexagonal boss 225 facing away from terminal link 214. Terminal link214, in turn includes hexagonal socket 224 facing away from terminallink 202. As depicted, flexible hinges 231, 233 and 235 are orientedorthogonal to flexible hinges 232, 234 and 236. As shown, the linksfurther include channels 228 that receive the individual cables setsthat control the links. The member is designed such that the cables willpass through cable channels in the links and terminate and be affixed toterminal link 202 of flexible segment 216. Specifically, the cables canexit channels 228 at exit points 229 and be affixed to recess 223 oflink 202. Flexible segment 216 then acts as an active flexible segmentwith the remaining flexible segments being spacer flexible segments.Alternatively, a cable set could terminate any one of the other flexiblesegments, making any other flexible segment an active flexible segment.Also, while cable channels 228 are shown arranged in a circular pattern,such a pattern is not critical, as each channel can be located at anyradial location along the member. Center channel 227 extends axiallythrough the flexible member to accommodate additional elements of anytools or instrument associated with the flexible member or with anyarticulating mechanism that includes the flexible member. Alternatively,a similar channel could be provided at any other radial location alongthe member, including its perimeter. The flexible member can beincorporated into or form all of or a portion of the proximal and distalends of an articulating mechanism according to the invention.

The flexible hinge system has a variety of important advantages. One isease of manufacture and assembly, as the flexible segments, flexiblemembers, or the articulating mechanism or portions thereof can bemanufactured as single continuous piece having multiple links connectedby the flexible hinges. In addition, multiple flexible segments ormembers of the same or differing configurations can be readily connectedtogether to create a wide variety of articulating mechanisms, thecharacteristics of which will depend in part on the component flexiblesegments or members used. In the embodiment depicted in FIGS. 2A-2C, thereciprocating boss 225 and socket 224 allow multiple flexible members tobe connected to each other, but one of skill in the art will appreciatethere are a variety of reciprocating structures that can achieve thesame purpose. A further advantage provided by the flexible hinge systemis an increased ability to transmit torque along the mechanism. Inmechanisms having individual links that are connected only by the cablesets, torque is less easily transmitted, as the force applied will causesome degree of twisting of the cables. Also, the flexible hinge systemsallow the application of an axial load along the mechanism withoutcompromising actuation. Articulation of the mechanism remains smooth andfacile even under axial load. This is not the case in some othermechanisms where individual links are in frictional contact with oneanother and where an axial load increases frictional forces between thelinks, which causes a restriction in movement or in some cases cause thelinks to “lock up” entirely.

To achieve the greatest freedom of motion, at least one flexible hingeof the mechanism, flexible member or flexible segment is orientedorthogonal to at least one of the other flexible hinges. However, inapplications where a more limited freedom of motion is acceptable, theflexible hinges need not be orthogonal. In the depicted embodiments ofFIGS. 1-2, consecutive hinges are orthogonal to one another but theinvention contemplates other configurations, including configurationswhere two or more consecutive hinges are oriented parallel to each otheror are offset from each other anywhere from 0-90 degrees.

Turning to FIGS. 3-5, embodiments of flexible segments are depictedwhere the flexible hinges bend or flex at predetermined positionsrelative to the adjacent connected links. The links otherwise have thesame overall diameter, the same diameter or distance between cablechannels, and the same gap between the links. When incorporated into anarticulating mechanism, the predetermined flex location between thelinks can have a positive, neutral or negative effect, or bias, on therelative tautness of cables passing through the link. More particularly,when a flexible segment bends due to an actuating force applied by acable or cables along one side of the links of a segment, the relativetautness of cables passing through the other side of the links can beaffected in a positive, negative or neutral manner. This effect, orbias, can also be referred to as “cable pull bias.” Flexible segmentsthat create or increase cable tension when the segment links arearticulated are said to have “positive bias.” Alternatively, flexiblesegments that result in decreased cable tension or slack when thesegment links are articulated are referred to as having a “negativebias,” Flexible segments that minimize cable tension and cable slack aresaid to have “neutral bias.” Depending on the application, suchpositive, neutral or negative effects can be advantageous. Theparticular predetermined flex locations to achieve positive, neutral ornegative cable pull bias will depend on the particular dimensions of agiven pair of links and the connecting hinge or hinges, including thediameter of the cable channel pattern, the gap between the links wherecables are exposed, and the maximum flex angle of the links. Theseparticular predetermined flex locations can be measured as a particularoffset (positive or negative) relative to the link surface where thecables emerge or exit from the cable channels. In operation, when thelinks of a flexible segment are manipulated into a desired position orconfiguration, the flexible hinge between two given links flexes orbends, such that the two links are flexing or bending toward or awayfrom one another about the hinge. Under a neutral bias configuration,the distance a given cable channel exit point on one link moves towardsits corresponding cable channel exit point on the other link is equal tothe distance the opposing cable channel exit point on the opposite sideof the link moves away from its corresponding cable channel exit pointon the other link. The combined distance between the two respective setsof cable channel exit points, however, remains constant whether or notthe segment is flexed, which is important to maintaining neutral cablebias. Where such combined distances are not equal, an increase in cableslack or tension can occur. Particularly, where the combined distancebetween sets of opposing channel exit points is greater when the linksare flexed as compared to the combined distance in the straight,non-bent position, cable tension can occur. Alternatively, where thecombined distance between sets of opposing channel exit points islessened upon flexing or bending relative to a straight, non-bentposition, cable slack can occur.

In the embodiment depicted in FIGS. 3A-3C, flexible segment 240 includesflexible hinge 246 connecting links 244 and 245. The links also includecable channels 248. The links have a cable channel pattern diameter ofD, and are separated by gap G between the links where cables areexposed. The links have a maximum flex angle of T about hinge 246. Inthe situation where D is five times G, and T is 20 degrees, the desiredpredetermined flex position for neutral cable pull bias is an offsetO.sub.1 of 1/100 D, which is practically at or near surface face 247 oflink 245 where the cables emerge or exit from the cable channels. Inother words, in this situation the flex position is aligned or nearlyaligned with the surface portion of link 245 where the cables emerge orexit. In this particular configuration, cable slack is minimized overthe range of motion of the segment. By minimizing cable slack, themechanism can retain its shape over a range of motion and resist counterforces applied against the mechanism that would compromise shapeaccuracy. This will be advantageous in most applications. Configurationsof flexible hinges that minimize slack in the cables are said to have a“neutral bias.”

In the embodiment of FIGS. 4A-4C, flexible segment 260 has flexiblehinge 266 with a predetermined flex position located between twoadjoining links 264 and 265. Links 264 and 265 contain cable channels268. In this configuration, the flexible hinge has a positive offsetO.sub.2 relative to the surface 267 of link 265. In the situation wheredimensions D, G and T are as above, this flex position leads to anegative cable pull bias. That is, when the segment bends at these linksdue to an actuating force applied by a cable or cables along one side ofthe links there is typically slack created in the cable or cables alongthe opposite side of the links. In some applications, this creation ofslack may be desirable as it will decrease the rigidity of the device inthat area, and limit its resistance to counter forces deployed alongthat area. Examples where this could be desirable include navigation ofthe mechanism through or around sensitive or fragile anatomicalstructures. Flexible hinges that allow for some degree of slack in thecables are said to have a “negative bias.”

The embodiment of FIGS. 5A-5C, flexible segment 280 includes flexiblehinge 286 connecting links 284 and 285. Links 284 and 285 likewiseinclude cable channels 288. In this configuration, the flex position hasa negative offset O.sub.3 relative to surface 287 of link 285, That is,the flex position is below the surface portion of link 285 where thecables emerge or exit. In the situation where dimensions D, G and T areas above, this flex position leads to a positive cable pull bias. Thatis, when the segment bends at these links due to an actuating forceapplied by a cable or cables along one side of the links there istypically tension created in the cable or cables along the opposite sideof the links. In some applications, this creation of tension may bedesirable as it will increase the rigidity of the device in that areaand resist any applied counter force. Such tension can further provide aresistance to further bending of the mechanism, and provide feedback tothe user. Examples where this could be desirable include applicationswhere it is important to guard against too much bending or “overbending”of the mechanism. Flexible hinges having this configuration that createadditional tension in the cables are said to have a “positive bias.”

FIG. 6 depicts another embodiment of the invention, with articulatingmechanism 300 with proximal and distal ends 321, 322, respectively, andspacer element 325 disposed there between. Distal end 322 includesflexible segments 316, 318, 320, 322 and 324 formed by a series of links302, 304, 306, 308, 310, and 312 connected by flexible hinges 317, 319,321, 323, and 325, respectively. Proximal end 321 includes flexiblesegment 314 formed by links 301 and 303 connected by flexible hinge 315.As depicted, the flexible hinges are all oriented parallel to oneanother along the longitudinal axis of the unactuated mechanism (asrepresented by axis Z). In this manner, the mechanism can provide fortwo-dimensional movement, but not three dimensional movement. The linksfurther include channels that receive cables 331 and 332 that form thecable set that controls actuation of the mechanism. As above, themechanism is designed such that the cables will pass through cablechannels in the links. The cables are secured to distal terminal link302 of flexible segment 316 and to proximal terminal link 301 offlexible segment 314. Flexible segments 316 and 314 thus act as anactive flexible segment pair with the remaining flexible segments beingspacer flexible segments.

FIG. 6 shows articulating mechanism 300 in an actuated or manipulatedcondition. As seen proximal flexible segment 314 at proximal end 321 hasbeen flexed about an angle of W. Due to the addition of the spacersegments at distal end 322, the entire distal end flexes about theequivalent angle W, but the angle between each flexible segment islessened such that the angles in the cumulative match angle W. However,the distance Y that distal end 322 travels relative to the original axisline Z of the mechanism, is proportionally greater than the distance Xthat distal end 321 travels relative to axis Z. This illustrates how theaddition (or subtraction) of spacer segments can result in achievingsame overall angle of bend but across a greater (or lesser) lateraldistance.

FIG. 7 depicts further embodiment of the invention, with articulatingmechanism 350 having proximal and distal ends 371, 372, respectivelyseparated by spacer element 375. Distal end 372 includes flexiblesegment 362 formed of links 352 and 354 connected by flexible hinge 356.Proximal end 371 includes flexible segment 361 formed by links 351 and353 connected by flexible hinge 355. Again the flexible hinges are alloriented parallel to one another along the longitudinal axis (not shown)of the unactuated mechanism, again providing for two-dimensionalmovement, but not three dimensional movement. The links further includechannels that receive cables 381 and 382 that form the cable set thatcontrols actuation of the mechanism. Again, the mechanism is designedsuch that the cables will pass through cable channels in the links. Thecables are secured to distal terminal link 352 of flexible segment 362and to proximal terminal link 351 of flexible segment 361. Flexiblesegments 362 and 361 thus act as an active flexible segment pair. Asdepicted, the diameter K between cable channels of links 351 and 353 atthe proximal end is larger than diameter J of corresponding links 352and 354 at the distal end.

As shown, articulating mechanism 350 in an actuated or manipulatedcondition. As seen, proximal flexible segment 361 at proximal end 371has been flexed about an angle of H. However the distal flexible segment362 flexes about a larger angle of P. This is due to the change indiameter between cable channels between the proximal and distal links.The change in flex angle is generally proportional to the diameterdifferences, with angle P being proportional to angle H multiplied bythe ratio of the two diameters (i.e., P.congruent.H.times.(K/J)). Forany two link pairs then, the difference can be expressed in terms of theresulting pivot angle that results when the links are manipulatedrelative to their unpivoted state. Thus, for any given link pair L.sub.1and L.sub.2 having differing cable channel location radii of R.sub.1 andR.sub.2, respectively, from the center axis of the links and whereR.sub,2>R.sub.1, when L.sub.1 is pivoted to an angle of A.sub.1,corresponding link L.sub.2 will have a resulting pivot angleA.sub.2=A.sub.1.times.sin.sup.−1 (R.sub.1/R.sub.2). This illustrates howthe increase or decrease of cable channel pattern diameter or radii canproportionally increase or decrease the angle of bend or flex in themechanism. This can have important ergonomic applications, including insurgical applications where a smaller angle of flex at the useroperating, proximal end can result in a greater angle of flex or bend atthe distal end, allowing for exaggerated or increased movement of thedistal end to deploy and/or actuate surgical tools or instruments. Inother applications it may be desirable for the user operating proximalend to have a larger angle of flex relative to the distal end.

Consistent with the above considerations, the links may further be ofany size and shape, as the purpose dictates. For surgical applications,the size and shape of links usually depends on such factors as patientage, anatomy of the region of interest, intended application, andsurgeon preference. Links are generally, but need not be, cylindrical,and as previously mentioned include channels for passage of the cablesthat connect the flexible segment pairs as well as additional cables,wires, fiberoptics or other like elements associated with a desired toolor instrument used in conjunction with the mechanism. The channeldiameters are usually slightly larger than the cable diameters, creatinga slip fit. Further, the links may also include one or more channels forreceiving elements of attachable surgical instruments or diagnostictools or for passage of cables that actuate them. The links maytypically have a diameter from about 0.5 rum to about 15 mm or moredepending on the application. For endoscopic applications,representative diameters may range from about 2 mm to about 3 mm forsmall endoscopic instruments, about 5 mm to about 7 mm for mid-sizedendoscopic instruments, and about 10 mm to about 15 mm for largeendoscopic instruments. For catheter applications, the diameter mayrange from about 1 mm to about 5 min. Overall length of the links willvary, usually depending on the bend radius desired between links.

The articulating mechanism, flexible members and flexible segments maybe formed of a number of materials known in the art and that can varyaccording to the application. For ease of manufacture, injectionmoldable polymers can be used including, e.g., polyethylene orcopolymers thereof, polyethylene terephthalate or copolymers thereof,nylon, silicone, polyurethanes, fluoropolymers, poly (vinylchloride);and combinations thereof, or other suitable materials known in the art.

For surgical applications a lubricious coating may be placed on thelinks or segments if desired to facilitate advancement of thearticulating mechanism. The lubricious coating may include hydrophilicpolymers such as polyvinylpyrrolidone, fluoropolymers such astetrafluoroethylene, or silicones. A radioopaque marker may also beincluded on one or more segments to indicate the location of thearticulating-mechanism upon radiographic imaging. Usually, the markerwill be detected by fluoroscopy.

Cable diameters vary according to the application. For surgicalapplications in general, cable diameters and may range from about 0.15mm to about 3 mm. For catheter applications, a representative diametermay range from about 0.15 min to about 0.75 mm. For endoscopicapplications, a representative diameter may range from about 0.5 mm toabout 3 mm.

Cable flexibility may be varied, for instance, by the type and weave ofcable materials or by physical or chemical treatments. Usually, cablestiffness or flexibility will be modified according to that required bythe intended application of the articulating mechanism. The cables maybe individual or multi-stranded wires made from material, including butnot limited to biocompatible materials such as nickel-titanium alloy,stainless steel or any of its alloys, superelastic alloys, carbonfibers, polymers, e.g., poly (vinylchloride), polyoxyethylene,polyethylene terephthalate and other polyesters, polyolefin,polypropylene, and copolymers thereof; nylon; silk; and combinationsthereof, or other suitable materials known in the art.

The cables may be affixed to the flexible segments of an active pairaccording to ways known in the art, such as by using an adhesive or bybrazing, soldering, welding, and the like, including methods describedin pending and co-owned U.S. application Ser. Nos. 10/444,769 and10/928,479, incorporated herein by reference in their entirety.

Although the many articulating mechanisms and flexible members that havebeen illustrated in the accompanying figures have a certain number offlexible segments and flexible segment pairs, this is solely for theillustrative purpose of indicating the relationship of the individualmechanism or flexible segment components to one another. Any number offlexible segments and flexible segment pairs may be employed, dependingon such factors as the intended use and desired length of thearticulating mechanism.

The natural configuration of the articulating mechanisms, flexiblemembers or flexible segments is usually linear, although if desirablethe mechanisms, flexible members or flexible segments can bemanufactured to have a pre-formed bend. If maintenance of a certaincurvature or other complex configuration is desired at the distal end ofthe articulating mechanism, the mechanism can be “locked” into placeaccording to ways described e.g. in pending and co-owned U.S.application Ser. Nos. 10/444,769 and 10/928,479, incorporated herein byreference in their entirety. For example, a malleable tube slidable overthe proximal segments may be shaped to keep the proximal segments, andthus, their corresponding distal segments in a particular configuration.This may be advantageous where, for example, a user has navigated themechanism to a desired target location and wishes to “lock” themechanism in place while e.g. actuating a tool associated with themechanism, or engaging in a separate procedure altogether. By the term“malleable” it is meant that the tube is flexible enough so that it iscapable of being shaped, but rigid enough so that it maintains itsshaped form. In another variation, a locking rod may be inserted intoone or more attachment channels extending through the flexible segmentsor segments to “lock” the proximal and distal segments of thearticulating mechanism in place. The locking rod may be a malleablemetal bar that may be shaped and then inserted into the attachmentchannels to set the proximal and distal segments into a particularconfiguration, or the locking rods may be provided in preshaped forms.In a further variation, the flexible segments or members themselves maybe formed of a malleable material that retains its shape oncemanipulated into the desired configuration.

As noted, the articulating mechanisms of this invention may be used todirect a surgical or diagnostic instrument tool within a body region orto a target site within a body region of a patient either in its native,straight configuration, or after undergoing various manipulations at itsproximal end from a location outside the patient. After appropriateinsertion, movement of the proximal end of the mechanism, results inreciprocal movement at the distal end. Further, the resultingdirectional movement of the distal end can be inverted, mirrored orotherwise, depending on the degree of rotation of the proximal endrelative to the distal end. Also, the proximal end provides for a userinterface to control the steering and manipulation of the distal endthat is convenient and easy to use relative to other conventionalsteering mechanisms that rely on e.g., pulleys or knobs to controlsteering wires. This user interface allows for example a user to readilyvisualize the shape and directional movement of distal end of themechanism that is located e.g. within a patient based on the manipulatedshape of the externally positioned proximal end user interface. In afurther variation, the flexible segments or members themselves may beformed of a malleable material that retains its shape once manipulatedinto the desired configuration.

The articulating mechanism may be employed for remote manipulation ofsurgical instruments, diagnostic tools, various catheters, and the like,into hollow or chambered organs and/or tissues including, but notlimited to, blood vessels (including intracranial vessels, largevessels, peripheral vessels, coronary arteries, aneurysms), the heart,esophagus, stomach, intestines, bladder, ureters, fallopian tubes, ductssuch as bile ducts, and large and small airways. The articulatingmechanism may also be used to remotely direct surgical instruments,diagnostic tools, various catheters, and the like, to solid organs ortissues including, but not limited to, skin, muscle, fat, brain, liver,kidneys, spleen, and benign or malignant tumors. The articulatingmechanism may be used in mammalian subjects, including humans (mammalsinclude, but are not limited to, primates, farm animals, sport animals,cats, dogs, rabbits, mice, and rats).

Turning to FIGS. 8-12, an embodiment of the invention is depicted whichincorporates an articulating mechanism with flexible segments into asurgical instrument. FIG. 8A illustrates a surgical grasping instrument400 which includes an elongate shaft 405 which separates proximal anddistal flexible members 406 and 407, respectively. The flexible membersare as described above, with multiple cables associated with discreteflexible segments such that movement of the proximal end results incorresponding movement of the distal end. Actuating handle 402 islocated at the proximal end of proximal flexible member 406, and has astandard ratchet handle interface with pivoting arms 403 and 404 thatare pivotable toward and away from one another. The distal end of arm403 is fixedly secured to the proximal end of proximal flexible member406. Grasping tool 410 is attached at the distal end of distal flexiblemember 407. As more clearly shown in FIG. 8B, grasping tool 410 includesupper and lower jaws 412 and 414 that are connected to jaw housing 416,with base 418 of housing 416 being fixedly secured to the distal end ofdistal flexible member 407.

More particularly, jaw housing 416 includes opposed parallel extendingwalls 420 and 422 with the proximal ends of jaws 412 and 414 positionedbetween the walls. As seen most clearly in FIGS. 8B-11B, each jawincludes slots that receive pins that span the space between the twowalls. Specifically, upper jaw 412 includes slots 452 and 456 thatreceive pins 423 and 424, respectively. Lower jaw 414 includes slots 454and 458 that receive pins 425 and 426. The slots of each jaw areoriented at an angle relative to the distal grasping portion of the jawsand are generally parallel to one another over most of the length ofeach slot. As can be seen however with particular reference to FIGS. 10Band 11B, both slots 452 and 454 have proximal terminal portions 453 and455 respectively that diverge from parallel relative to respective slots456 and 458. This will have an important impact on jaw movement asfurther discussed below. Jaws 412 and 414 also include notches 457 and459, with notch 457 located between slots 452 and 456 on jaw 412 andnotch 459 located between slots 454 and 458 on jaw 414. These notches457 and 459 accommodate pins 424 and 426, respectively, when the jawsare in the closed position (see FIG. 9B). Jaws 412 and 414 are alsopivotally connected to link arms 436 and 438, respectively, which inturn are pivotally connected at their other ends to cable terminator430, which likewise resides within housing 416 and between walls 420 and422. Actuating cable 432 is connected to and terminates at cableterminator 430 with cable 432 itself extending proximally through thejaw housing 416 and through a central channel (not shown) that extendsthrough flexible member 407, elongate shaft 405, and terminates at itsother end at arm 404 of handle 402. Bias spring 434 is aligned axiallywith cable 432 and is disposed between cable terminator 430 and base 418of jaw housing 415. Jaws 412 and 414 themselves include opposing jawsurfaces 442 and 444, respectively. The jaw surfaces are each providedwith channels 446 and 448 respectively that can receive e.g. an energysource suitable for ablating tissue.

The configuration of the jaw and jaw housing connection providesimportant advantages as it allows for parallel movement of the jaws overa first range of motion while further allowing for the jaws to divergein a non-parallel fashion over a second range of motion. This overallrange of motion can be observed by reference to FIGS. 9-11, with thejaws able to move from a closed position (FIGS. 9A-9B) to a first openposition (FIGS. 10A-10B) while remaining parallel to each other at alltimes during such movement. From this first open position, the jaws canthen move in a non-parallel fashion to a second open position (FIGS.11A-11B). In this second open position, the distal tips of the jaws havediverged further from one another relative to the proximal ends of thejaws, creating a larger opening between the jaws at the tips, similar towhat occurs with jaws that are connected by a single pivot. This largeropening is advantageous as it facilitates navigating the jaws aroundtarget tissue or anatomy. At the same time, the jaws maintain a parallelmovement relative to each other upon closing from the first openposition (FIGS. 10A-10B) to the closed position (FIGS. 9A-9B), whichprovides a variety of advantages, including an even force distributionacross the jaws as they are closed upon target tissue. In addition,where an energy source is attached to the jaws for e.g. ablation, theparallel movement of the jaws allows for a more uniform transfer ofenergy to the tissue along the length of the jaws, providing moreuniform and consistent ablation.

This overall range of motion is achieved as follows. As can be seen,bias spring 434 is positioned to continually bias the jaws apart fromeach other in the open position. The spring bias can be overcome byactuating handle 402 to translate cable 432 and connected cableterminator 430 toward the proximal end of the instrument, bringing thejaws into the closed position depicted in FIGS. 9A-9B. As tension on thecable is released, the jaws are biased open from the closed position tothe first open position (FIGS. 10A-10B), the jaws remain parallel asupper and lower jaws 412 and 414 translate in directions parallel toslots 452, 456 and 454, 458, respectively, as slots 452, 456 and 454,458 translate relative to pins 423, 424 and 425, 426, respectively.During this range of motion, the terminal ends of link arms 436 and 438that are coupled to cable terminator 430 also translate, but any forceexerted by the link arms that would result in non-parallel movement isovercome by the restraining force of pins 423, 424 and 425, 426 retainedin parallel slots 452, 456 and 454, 458, respectively. However, as thejaws are further biased open, pins 423 and 425 relatively translate intothe terminal portions 453 and 455 of slots 452 and 454, respectively,which diverge from parallel relative to respective slots 456 and 458.Relative movement of the pins into these non-parallel portions allowslink arms 436 and 438 to pivot as well as translate, resulting in thedivergent movement of jaws 412 and 414 relative to each other as thejaws move to the second open position (FIGS. 11A-11B).

In yet a further variation, the articulating mechanism and flexiblesegments of the invention can be incorporated into a catheter and usedto guide the catheter. As shown in FIGS. 16A and 16B, catheter 700incorporates an articulating mechanism with the distal end of themechanism 702 integral with the distal end of the catheter, and theproximal end formed of flexible member 704 extending from handle 706.Proximal end flexible member 704 is formed of flexible segments 711, 713and 715 similar to those described herein. Distal end sections 712, 714,and 716 are integrally formed sections of the distal end 702 of thecatheter. Cable sets (not shown) connect distal end sections 712, 714,and 716 to proximal end segments 711, 713 and 715, such that distal end702 can be remotely maneuvered by manipulating proximal end flexiblemember 704 in order to guide the catheter 700 as advanced. As seen moreclearly in FIG. 16B, the distal end of catheter 700 includes a cathetertube with a central lumen 724 and multiple cable channels 728 thatextend the length of the catheter and that can receive cable sets (notshown) that connect the distal and proximal segments. The central lumencan provide passage for e.g., wires, energy sources, or other controlelements to the catheter tip, or function as through lumen for thepassage of fluids, or can otherwise provide for known functions ofcatheter lumens. The cables can be anchored within the catheter tube atthe desired locations as described in pending and co-owned U.S.application Ser. No. 10/444,769, incorporated herein by reference in itsentirety. Each distal end segment of the catheter can be formed ofmaterial having a different durometer and/or can be of varying lengths,which can provide an additional level of control when manipulating thecatheter. For example, if the distal-most section were of the lowerdurometer relative to the proximal most section, then control of thedistal tip would be enhanced as less cable force would be required toarticulate the distal-most section relative to the force required toarticulate the proximal most section. In alternative embodiments, thedistal end segments can be formed of discrete sections of catheter tubematerial that abut one another and which are maintained in positionrelative to one another by the passage and affixing of the cable setswithin the sections. Further, while catheter 700 includes proximal endflexible member 704 formed of flexible segments as described herein, itis further contemplated that the proximal end can alternatively beformed of a wide variety of articulating link systems that are similarlyconnected to the distal end through cable sets. Such articulating linksystems include, but are not limited to, those described in pending andcommonly owned U.S. application Ser. Nos. 10/444,769 and 10/928,479,incorporated herein by reference in their entirety.

FIGS. 12-13 depict a flexible segment according to another embodiment ofthe invention. As shown in FIG. 12, flexible segment 500 includes twoflexible hinges 506 and 508 that connect links 502 and 504, andotherwise shares many features of the previously described flexiblesegments. Cable channels 512 are provided for passage and receipt ofcables for controlling the segment itself or other segments. Centralchannel 510 is also provided. As more particularly shown in FIG. 13,flexible segment 500 is formed of two components, inner core 520 andouter cover 540. The provision of a flexible segment formed of innercore and outer cover components provides manufacturing advantages, aswill be further described. Inner core 520 is configured to be receivedaxially within outer cover 540. Inner core 520 includes link sections522 and 524 that are each generally cylindrical. Flexible hinge sections526 and 528 connect each link section to wing sections 534 and 536 whichtogether form another generally cylindrical portion aligned with anddisposed between the two link sections, and which when combined with thelink sections provide for central channel 510 of the formed flexiblesegment 500. The inner core also includes alignment flanges 530 and 532that extend lengthwise along the outer surface of the core. Outer cover540 likewise includes link sections 542 and 544 that are also generallycylindrical. Flexible hinge section 546 and 548 connect each linksection to stem sections 554 and 556 which are aligned with and disposedbetween the two link sections. Extending lengthwise along the interiorsurface of outer cover 549 is a series of cable slots 558. The outercover 540 also includes alignment slots 550 and 552 that extendlengthwise along the interior surface of the cover, with slots 550 inparticular extending along stems sections 554 and 556. These slotsreceive alignment flanges 530 and 532 respectively of inner core 520,such that when the inner core and outer cover are assembled together,the respective link sections and flexible hinge sections of the innercore and outer cover are in alignment with each other to form the linksand flexible hinges of the formed flexible segment 500, as well asforming cable channels 512. Specifically, link sections 522 and 542 formlink 502, flexible hinge sections 526 and 546 form flexible hinge 506,flexible binge sections 528 and 548 form flexible hinge 508, and linksections 524 and 544 form link 504. The outer surface of inner core 520abuts the inner surface of outer cover 540, sealing off cable slots 558lengthwise, and thereby forming cable channels 512.

For flexible segments and members formed through molding processes, themanufacture of an inner core and outer cover components can be simplerand more economical process than manufacturing the flexible segments ormembers as a single component. For example, molding flexible segmentshaving cable channels as a single component requires the use of manysmall core-pins that run the entire length of the part as part ofmolding process. Molding outer cover components with cable slots is asimpler process, with the mold cavity itself providing for the slots.Further, while the depicted embodiment of FIG. 1243 is a dual or doubleflex hinge link segment, it can be easily appreciated that a widevariety of flexible hinge links, segments, and flexible members can beformed from inner core and outer cover components, including but notlimited to the other links, segments and members described herein.Additionally, other links and link systems arly be formed of inner coreand outer cover components.

The particular configuration of flexible segment 500 also achieves otheradvantages. In particular, the dual hinge configuration of flexiblesegment 500 also provides for neutral cable bias, similar to the fashionprovided by neutral cable bias dual-pivoting link systems described inpending and commonly owned U.S. application Ser. No. 10/928,479,incorporated herein by reference in its entirety. With reference to FIG.12, it can be appreciated that flexible hinges 506 and 508 or flex orbend at locations that generally coincide with opposing faces of eachlink 502 and 504, and thus further coincide with cable channel exitpoints where actuating cables would exit from each respective link. Whenthe flexible segment is manipulated into a desired position orconfiguration, each flexible hinge flexes or bends, such that the twolinks are flexing or bending toward or away from one another about thedual hinges. Further, as a result of such dual flexing action, thedistance a given cable channel exit point on one link moves towards itscorresponding cable channel exit point on the other link is equal to thedistance the opposing cable channel exit point on the opposite side ofthe link moves away from its corresponding cable channel exit point onthe other link, similar to neutral cable bias flexible segmentsdescribed above. The combined distance between the two respective setsof cable channel exit points, however, remains constant whether or notthe segment is flexed, which is important to maintaining neutral cablebias. Where such combined distances are not equal, an increase in cableslack or tension can occur. Particularly, where the combined distancebetween sets of opposing channel exit points is greater when the linksare flexed as compared to the combined distance in the straight,non-bent position, cable tension can occur. Alternatively, where thecombined distance between sets of opposing channel exit points islessened upon flexing or bending relative to a straight, non-bentposition, cable slack can occur.

Other advantages offered by the configuration of flexible segment 500include wing sections 536 and 534, which can function as stops toprevent overflexing of the hinge regions. When flexible segment 500 isbent or flexed, opposing sides of links 502 and 504 will move towardeach other until they contact one or the other wing section, restrictingfurther bending movement. So for example, for a flexible segmentdesigned for a total maximum bend angle of 60 degrees, the wing sectionswould be configured to limit each flexible hinge to a maximum of 30degrees. This is illustrated more clearly with reference to FIGS. 14-15,which depict flexible segment 600, which is similar to flexible segment500 but is of single unit construction. Similar to flexible segment 500,flexible segment 600 includes two links 602 and 604 connected byflexible hinges 606 and 608. Cable channels 612 are provided for passageand receipt of cables and central channel 610 is also provided. Morespecifically, flexible hinges 606 and 608 connect links 602 and 604,respectively, to wing sections 624 and 626 disposed between and alignedwith the two links. Stem sections 614 and 616, which extendlongitudinally from the wing sections, are also connected to and alignedwith links 602 and 604. As depicted most clearly in FIG. 15B, wingsection 624 acts as a stop to limit further bending of flexible segment600.

The invention also contemplates kits for providing various articulatingmechanisms and associated accessories. For example, kits containingarticulating mechanisms having different lengths, different segmentdiameters, and/or different types of tools or instruments may beprovided. The kits may optionally include different types of lockingrods or malleable coverings. The kits may be further tailored forspecific applications. For example, kits for surgical application can beconfigured for, e.g., endoscopy, retraction, or catheter placement,and/or for particular patient populations, e.g., pediatric or adult.

All publications, patents, and patent applications cited herein arehereby incorporated by reference in their entirety for all purposes tothe same extent as if each individual publication, patent, or patentapplication were specifically and individually indicated to be soincorporated by reference. Although the foregoing invention has beendescribed in some detail by way of illustration and example for purposesof clarity of understanding, it will be readily apparent to those ofordinary skill in the art in light of the teachings of this inventionthat certain changes and modifications may be made thereto withoutdeparting from the spirit and scope of the appended claims.

1-20. (canceled)
 21. A surgical tool comprising: a pair of opposing jawsmoveable relative to each other between a closed position and first andsecond open positions, the opposing jaws remaining substantiallyparallel to one another when moving between the closed position and thefirst open position and remaining non-parallel to one another whenmoving between the first open position and the second open position. 22.The surgical tool of claim 21, wherein each of the opposing jawsincludes first and second slots that receive first and second pins thatextend from a jaw housing, and wherein the first and second slots areparallel to one another over a first length of each slot and arenon-parallel to one another over a second length of each slot.
 23. Thesurgical tool of claim 21, wherein opposing jaw surfaces of the pair ofopposing jaws each include channels for receiving an energy source. 24.The surgical tool of claim 21, wherein in the closed position, a gap ismaintained between the pair of opposing jaws.
 25. The surgical tool ofclaim 21, wherein in the second open position, a distance between adistal tip of each of the opposing jaws is greater than a distancebetween a proximal end of each of the opposing jaws.
 26. The surgicaltool of claim 21, wherein the opposing jaws remain substantiallyparallel to one another when moving between the first open position andthe closed position.
 27. The surgical tool of claim 26, wherein a forceis distributed substantially evenly across each of the opposing jaws asthe pair of opposing jaws moves from the first open position to theclosed position to close upon a target tissue.
 28. The surgical tool ofclaim 21, further comprising a spring, the spring being positioned toprovide a biasing force to continually bias the pair of opposing jawsapart from one another in the second open position.
 29. The surgicaltool of claim 28, wherein the biasing force can be overcome to bring thepair of opposing jaws into the closed position by actuating a handle totranslate a cable and a cable terminator in a longitudinal directiontoward a proximal end of the surgical tool.
 30. The surgical tool ofclaim 29, wherein the spring is axially aligned with the cable.
 31. Thesurgical tool of claim 22, wherein as the pair of opposing jaws movesfrom the closed position to the first open position, each opposing jawtranslates in a direction substantially parallel to the first length ofthe first and second slots of each opposing jaw, respectively.
 32. Thesurgical tool of claim 22, wherein as the pair of opposing jaws movesfrom the first open position to the second open position, the first pinof each opposing jaw translates into a terminal portion of the firstslot of each opposing jaw, respectively.
 33. The surgical tool of claim21, further comprising: a first link arm; and a second link arm, whereina terminal end of the first link arm is pivotally coupled to one jaw ofthe pair of opposing jaws, and wherein a terminal end of the second linkarm is pivotally coupled to the other jaw of the pair of opposing jaws.34. The surgical tool of claim 33, wherein as the pair of opposing jawsmoves from the closed position to the first open position, each terminalend of the first and second link arms translates in a directionsubstantially parallel to a first length of first and second slots ofeach opposing jaw, respectively.
 35. The surgical tool of claim 34,wherein a proximal end of the first link arm and a proximal end of thesecond link arm are pivotally coupled to a cable terminator of thesurgical tool at a same point.
 36. The surgical tool of claim 35,wherein as the pair of opposing jaws moves from the first open positionto the second open position, the first and second link arms translate ina direction substantially parallel to the first length of the first andsecond slots of each opposing jaw, respectively, and the first andsecond link arms pivot about the same point where the proximal ends ofthe first and second link arms are pivotally coupled to the cableterminator.
 37. The surgical tool of claim 21, wherein the surgical toolis configured to implant staples into tissue.
 38. The surgical tool ofclaim 21, further comprising an energy source attached to at least oneof the opposing jaws.
 39. The surgical tool of claim 21, furthercomprising a cauterizing element.
 40. The surgical tool of claim 21,wherein the surgical tool is configured to implant sutures into tissuedisposed between the opposing jaws.